Electrically affixed transcervical fallopian tube occlusion devices

ABSTRACT

The invention provides intrafallopian devices and non-surgical methods for their placement to prevent conception. The efficacy of the device is enhanced by forming the structure at least in part from copper or a copper alloy. The device is anchored within the fallopian tube by imposing a secondary shape on a resilient structure, the secondary shape having a larger cross-section than the fallopian tube. The resilient structure is restrained in a straight configuration and transcervically inserted within the fallopian tube, where it is released. The resilient structure is then restrained by the walls of the fallopian tube, imposing anchoring forces as it tries to resume the secondary shape.

This is a continuation of Ser. No. 08/474,779, filed on Jun. 7, 1995.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to contraception, and moreparticularly to intrafallopian contraceptive devices and nonsurgicalmethods for their delivery.

Worldwide demand exists for safe, effective methods of bothcontraception and permanent sterilization. Although a variety ofcontraception and sterilization methods are available, all of theexisting methods have limitations and disadvantages. Thus, the need foradditional safe, low cost, reliable methods of contraception andpermanent sterilization, both in developed and less developed countries,is widely recognized.

Many presently available contraception methods require significant userinvolvement, and user non-compliance results in quite high rates offailure. While the theoretical effectiveness of existing contraceptives,including barrier methods and hormonal therapies, is well established,overcoming user noncompliance to improve overall efficacy has provendifficult.

One form of contraception which is less susceptible to usernoncompliance is the intrauterine device (IUD). IUDs have been found tohave higher rates of reliability, and are effective for a longer periodof time, than most other commercially available contraceptives.Unfortunately, IUDs are also associated with serious infectiouscomplications. For this reason, the use of IUDs within the United Stateshas decreased dramatically. Additionally, IUDs are subject to unplannedexpulsion, and must be removed due to excessive pain or bleeding in apercentage of cases, further reducing the acceptance of the IUD as acontraceptive method. Interestingly, the efficacy of copper IUDs appearsto be higher than that of non-metallic IUDs. The reason for this has notbeen fully explained.

Commercially available options for permanent sterilization includefallopian tube ligation and vasectomy. These methods are surgical, aredifficult to reverse, and are not available to many people in the world.It is common knowledge that fertilization occurs in the fallopian tubeswhere the sperm and ovum meet. Tubal ligation avoids this by completeocclusion of the fallopian tubes.

It has previously been proposed to reversibly occlude the fallopiantubes, for example, by in vitro formation of an elastomeric plug, orotherwise anchoring a device on either side of the narrowest region offallopian tube, called the "isthmus." Such fallopian tube occlusionmethods appear promising; however, an unacceptably high percentage ofthe non-surgical devices proposed to date have become dislodged duringprevious studies. Even where non-surgical intrafallopian devices haveremained in place, they have been found to be only moderately effectiveat preventing conception.

For these reasons, it would be desirable to provide effective, reliableintrafallopian devices for contraception and sterilization. It would beparticularly desirable to provide highly effective intrafallopiandevices which did not require surgery for placement. It would beespecially desirable if such devices and methods allowed easy placementof the device, but were less susceptible to being dislodged thanpreviously proposed non-surgical intrafallopian devices.

2. Description of the Related Art

The experimental use of a stainless steel intrafallopian device isdescribed in Transcatheter Tubal Sterilization in Rabbits, Penny L.Ross, RT 29 "Investigative Radiology", pp. 570-573 (1994). Theexperimental use of an electrolytically pure copper wire as a surgicalcontraceptive intrafallopian device in rats was described in"Antifertility Effect of an Intrafallopian Tubal Copper Device", D. N.Gupta, 14 Indian Journal of Experimental Biology, pp. 316-319 (May1976).

U.K. Patent Application Pub. No. 2,211,095 describes a uterine screwplug for blocking the fallopian tube. European Patent Application Pub.No. 0,010,812 describes a device for placement in the oviducts havingenlargements at either end for anchoring the device. The same deviceappears to be described in Netherlands Patent No. 7,810,696.

The use of tubal occlusion devices is described in "HysteroscopicOviduct Blocking With Formed-in-Place Silicone Rubber Plugs", Robert A.Erb, Ph.D., et al., The Journal of Reproductive Medicine, pp. 65-68(August 1979). A formed-in-place elastomeric tubal occlusion device isdescribed in U.S. Pat. No. 3,805,767, issued to Erb. U.S. Pat. No.5,065,751, issued to Wolf, describes a method and apparatus forreversibly occluding a biological tube. U.S. Pat. No. 4,612,924, issuedto Cimber, describes an intrauterine contraceptive device which sealsthe mouths of the fallopian tubes.

German Patent No. 28 03 685, issued to Brundin, describes a device forplugging a body duct with a device which swells when in contact with abody fluid.

Alternative contraceptive devices are disclosed in copending U.S. patentapplication Ser. No. 08/475,252, the full disclosure of which is hereinincorporated by reference.

SUMMARY OF THE INVENTION

The present invention provides intrafallopian devices and methods fortheir placement to prevent conception. The intrafallopian devices of thepresent invention are transcervically delivered, resiliently anchoredstructures which are formed at least in part from copper to provide longterm contraception, or alternatively permanent sterilization, withoutthe need for surgical procedures or the increased bleeding, pain, andrisks of infection associated with intrauterine devices (IUDs).

The use of copper in the intrafallopian device of the present inventionimproves its efficacy as a contraceptive method. Devices formed fromplastically deformable materials, however, are less readily restrainedin the fallopian tube. Apparently, the large variation in the actualshape and dimensions of fallopian tubes does not provide reliableanchoring for a pre-formed deformable intrafallopian device. Theintrafallopian device of the present invention therefore comprises aresilient structure, usually a metallic coil, which includes a copperalloy, a copper plating, or copper fibers, ideally comprising an alloyincluding at least 75% copper. The coil material typically includesberyllium, zinc, stainless steel, platinum, a shape memory alloy such asNitinol™, or the like. Preferably, the coil is composed of an alloy ofberyllium and copper. Although the present device will generally resultin occlusion, it need not completely occlude the fallopian tube toprevent the meeting of the sperm and ovum. Instead, the presence of thecopper on the resilient structure is sufficient to provide effectivecontraception.

Conveniently, the present invention further comprises non-surgicalplacement of such intrafallopian devices by transcervical introduction.The resilient structure is restrainable in a straight configuration,e.g., by inserting the device within a catheter, greatly facilitatingand reducing the risks of introduction. Thus, the cost and dangersassociated with existing surgical contraceptive and sterilizationprocedures are avoided.

In a first aspect, a contraceptive intrafallopian device according tothe present invention comprises a resilient structure having a proximalend and a distal end. The resilient structure comprises copper, and isbiased to form at least one bend near the proximal end of the primarycoil. Similarly, the resilient structure is also biased to form at leastone bend near its distal end. These proximal and distal bends define anisthmus-traversing region therebetween. Preferably, theisthmus-traversing region also includes at least one bend, therebyhelping to anchor the coil within the fallopian tube.

Generally, the resilient structure of the present intrafallopian devicewill be formed as a primary coil. To help restrain the coil within thefallopian tube, fibers are attached to some embodiments of the coil, thefibers optionally comprising a polyester material such as Rayon™,Dacron™, or the like. Alternatively, copper fibers may be used toincrease the exposed copper surface area, the copper fibers generallyhaving a diameter on the order of 0.001 inches.

The bends of the present intrafallopian device are generally formed as asecondary shape imposed on a primary coil. The primary coil is mosteasily formed as a straight cylindrical coil. The secondary shape willbe imposed on the primary coil by bending, optionally heat treating theprimary coil while bent. The individual bends may take a wide variety offorms, including sinusoidal curves, the individual loops of a continuoussecondary coil, or the like. However, the secondary shape generallydefines an overall width which is larger than the fallopian tube, sothat the tubal wall restrains the resilient structure when it isreleased.

Preferably, each of the bends of the present intrafallopian device formsa loop in the primary coil when in a relaxed state. Ideally, the loopsare separated by straight sections of coil. The alternating of loopswith straight sections of coil forms a large diameter "flower coil,"which provides a large relaxed overall width, and also features bends oftight radius, both of which promote retention. Conveniently, the primarycoil generally has a diameter less than that of the fallopian tube, andcan be restrained in a straight configuration for placement within thefallopian tube, typically by inserting the primary coil within adelivery catheter.

In another aspect, a contraceptive intrafallopian device according tothe present invention comprises a resilient primary coil having aprimary coil diameter. The primary coil comprises copper, and forms asecondary shape when in a relaxed state. The secondary shape defines aplurality of bends and an overall width which is larger than the primarycoil diameter. Thus the primary coil can be easily anchored in afallopian tube which is smaller in diameter than the secondary shape.Preferably, the present device reacts with a force sufficient to preventaxial movement of the device within the fallopian tube when restrainedin a lumen having a diameter in the range between 0.5 mm and 3 mm. Theactual anchoring force will depend on the shape of the coil and themodulus of elasticity of the material used.

In yet another aspect, a intrafallopian contraceptive delivery systemaccording to the present invention comprises an elongate body in whichthe resilient primary coil described above is slidably disposed. A shaftis also slidably disposed within the elongate body and is locatedproximally of the primary coil. The distal end of the shaft includes acoil interface surface, while the elongate body restrains the primarycoil in a straight configuration.

Preferably, a bend in the isthmus-traversing region of the presentintrafallopian device, together with the proximal and distal anchorbends, restrains the resilient structure within the isthmus of thefallopian tube. The distal anchor is inserted into the ampulla, distalof the isthmus, while the proximal anchor is located in the ostium,proximal of the isthmus. Unintended movement of the device is furtheravoided by locating the isthmus-traversing region within the isthmus toresiliently impose anchoring forces against the tubal wall.

In a still further aspect, an intrafallopian contraceptive methodaccording to the principles of the present invention comprisesrestraining a resilient structure in a straight configuration andtranscervically inserting the resilient structure into a fallopian tube.The resilient structure is affixed within the isthmus by releasing abent isthmus-traversing region. The bend of the isthmus-traversingregion exerts a force against the wall of the fallopian tube, anchoringthe device within the isthmus. Preferably, a distal anchor on theresilient structure is released distally of the isthmus, and a proximalanchor is released proximally of the isthmus, the distal and proximalanchors generally formed from bends in the resilient structure.Optionally, an electric current is applied through the resilientstructure to the fallopian tube, thereby effecting permanentsterilization.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a first embodiment of a contraceptive intrafallopiandevice according to the present invention having a single distal anchorloop, a single proximal anchor loop, and an isthmus-traversing regionhaving a single loop for anchoring the device within the fallopian tube.

FIG. 2 illustrates an alternative embodiment of a contraceptiveintrafallopian device according to the present invention having aplurality of loops which may act as proximal, distal, or lumen anchors.

FIG. 3 illustrates the distal portion of a delivery catheter forplacement of a contraceptive intrafallopian device according to thepresent invention.

FIG. 4 illustrates the contraceptive intrafallopian device of FIG. 1partially released from the delivery catheter of FIG. 3.

FIGS. 5 and 6 illustrate a contraceptive method using an intrafallopiandevice according to the principles of the present invention.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENT

The present invention encompasses a contraceptive intrafallopian devicewhich can alternatively be used as both a permanent and a reversiblemeans of contraception. The present contraceptive methods and devicesminimize the danger of non-use which has limited the efficacy of priorart contraceptive techniques. Moreover, the location of the presentdevices within the fallopian tubes provides a reduced risk of theinfectious complications, increased bleeding, and pelvic pain associatedwith intrauterine devices (IUDs). Furthermore, the location and thenovel shape of the present intrafallopian device provides significantadvantages over ILUDs, which have been found to be susceptible tounplanned expulsion and removal due to excessive pain and bleeding. Thepresent invention takes advantage of the increase in effectivenessassociated with copper IUDs, providing a resilient structure includingcopper which may be transcervically positioned without the need forsurgery.

Although the present contraceptive method may be included within a groupof contraceptive techniques generally referred to as fallopian tubeocclusion methods, the present invention does not necessarily relysolely on blocking the fallopian tube to prevent fertilization. Instead,contraception is apparently provided by disrupting of ovum transport,the process of fertilization, and/or cleavage of the ovum. While theeffect that copper has on these processes is not fully understood, itdoes appear that copper intrafallopian devices offer potentiallysignificant increases in effectiveness over intrafallopian devicesformed of other materials. Optionally, the present invention furtherencompasses devices which promote tissue growth within the tube toinduce tubal occlusion, further inhibiting conception.

The present invention is anchored within the isthmus of the fallopiantube, overcoming the unintended expulsion of the device and theresulting failure of the contraceptive method. Such intrafallopiandevice expulsion has been the single greatest factor limiting theefficacy of easily positioned intrafallopian contraceptive techniques.

The present intrafallopian devices are generally elongate resilientstructures pre-formed into secondary shapes. These secondary shapes willbias the resilient structure so as to provide strong forces against thelumen wall of the fallopian tube. Clearly, the secondary shape must havea larger outer diameter than the inner diameter of the fallopian tube.

Conveniently, the present resilient structures are insertable into acatheter, the catheter wall restraining the resilient structure in astraight configuration. As the resilient structure has an outer diameterwhen in the straight configuration which is less than the inner diameterof the fallopian tube, the catheter containing the presentintrafallopian device is easily transcervically introduced. Moreover,the device is readily removed by snaring the resilient structure nearthe proximal end and pulling proximally on the resilient structure,thereby straightening the resilient structure and allowing it to bewithdrawn without injuring the fallopian tube. Alternatively, anelectrical current is applied to the device after it is at leastpartially releasing the fallopian tube, providing permanentsterilization.

Referring now to FIG. 1, a first embodiment of the present contraceptiveintrafallopian device 10 is formed from a resilient primary coil 12.Primary coil 12 is most easily originally formed as a straightcylindrical coil or spring, preferably having an outer diameter in therange from 0.2 mm to 5 mm, and having a length in the range from 20 mmto 150 mm. Ideally, primary coil 12 has an outer diameter in the rangefrom 0.4 mm to 2 mm and a length in the range from 30 mm to 70 mm. Thestraight primary coil may then be bent into a variety of secondaryshapes.

The primary coil 12 of intrafallopian device 10 includes a proximal end14 and a distal end 16. Between these ends, three loops 20 are formed,each having an inner diameter 22. Located between loops 20 are straightsections 24, which increase the overall cross-section of theintrafallopian device to an overall width 26. Preferably, inner diameter22 is in the range from 2 mm to 10 mm, while overall width 26 is atleast 6 mm, ideally being in the range from 8 mm to 40 mm. Distal andproximal ends 14, 16 each include an atraumatic endcap 18 to preventinjury to the fallopian tube.

Preferably, primary coil 12 is formed from a beryllium copper alloywire. Beryllium copper provides the resilience necessary to avoidexpulsion of the device, and also provides the increased effectivenessof a copper contraceptive intrafallopian device. Alternatively, primarycoil 12 is formed from a resilient metal, such as stainless steel,platinum, a shape memory alloy, or the like. If such materials are used,primary coil 12 is preferably plated with copper or a copper alloy orotherwise has copper attached.

To further reduce the possibility of expulsion of intrafallopian device10, fibers are optionally carried on primary coil 12. The fibers may beshort individual fibers, or may alternatively be wound into primary coil12. Preferably, the fibers comprise copper, thereby increasing the totalcopper surface area. Such copper fibers are preferably bonded to primarycoil 12 with solder, brazing, a polymeric adhesive, or the like.Alternatively, polyester fibers such as Dacron™, Rayon™, or the like,are bonded to the surface of primary coil 12 using a polymeric adhesive.The polyester fibers promote increased tissue growth around the coil,thus further reducing the possibility of expulsion of the device fromthe fallopian tube.

A secondary shape has been superimposed on the primary coil to formintrafallopian device 10, the secondary shape comprising loops 20separated by straight sections 24. This secondary shape is hereinreferred to as a "flower coil." The flower coil shape is particularlyadvantageous in that outer diameter 26 is substantially larger than theprimary coil diameter, while the individual loops 20 have relativelysmall inner diameters 22 which will maintain the largest possibleanchoring force against the fallopian tube. Minimizing inner diameter 22also ensures that anchoring force is applied within the fallopian tube,despite the curvature of the fallopian tube.

Referring now to FIG. 2, an alternative embodiment of the presentcontraceptive intrafallopian device 30 includes additional loops toensure anchoring of the device within the fallopian tube. Alternativeembodiment 30 is formed from an elongate primary coil 32 having aproximal end 34 and a distal end (not shown). Elongate primary coil 32has an outer diameter 36 which is smaller than the isthmus of thefallopian tube, allowing the straightened intrafallopian device to beinserted easily. Elongate primary coil 32 has been bent to form asecondary shape including a larger number of loops 38 than theembodiment of FIG. 1. Loops 38 have an outer diameter 40 which is largerthan the inner diameter of the fallopian tube, preventing loops 38 fromassuming their relaxed shape. Loops 38 are again separated by straightsections 42 of elongate primary coil 32, increasing the overallintrafallopian device diameter 44.

In both embodiments of the present intrafallopian device 10, 30, atleast one loop adjacent to the proximal end is disposed proximally ofthe narrowest portion of the fallopian tube, referred to as the isthmus.Similarly, at least one loop of the intrafallopian device is disposeddistally of the isthmus. These proximal and distal loops act as anchors,helping to prevent proximal or distal movement of the intrafallopiandevice. In the embodiment of FIG. 2, at least one loop is also disposedadjacent to the isthmus of the fallopian tube, further helping toprevent unintentional expulsion.

Alternative intrafallopian device 30 may be positioned with multipleloops acting as proximal or distal anchors, or may alternatively haveall but the proximal and distal anchor loops disposed along thefallopian tube to act as anchors within the lumen of that body.Advantageously, the embodiment of FIG. 2 is therefore less sensitive tovariations in total fallopian tube length.

Referring now to FIG. 3, a delivery catheter for the presentintrafallopian device comprises an elongate body 52 and a shaft 54.Elongate body 52 includes a lumen 56 in which shaft 54 is disposed,shaft 54 being slidable in the axial direction. Shaft 54 includes a core58 having a tapered distal end 60, allowing the device to navigatethrough tortuous bends while retaining the column strength required toadvance the device. Core 58 extends proximally through elongate body 52,and is capable of transferring compressive forces through the elongatebody. Core 58 is typically formed from stainless steel, a stainlessalloy, or the like. Disposed over distal end 60 of core 58 is pusher cap62. Pusher cap 62 provides a low friction, deformable end piece having adistal coil interface surface 64. Pusher cap 62 is preferably formed ofa low friction polymer such as PTFE, or the like.

Intrafallopian delivery catheter 50 receives the present intrafallopiandevice within the distal end of lumen 56 of elongate body 52. Lumen 56has an inner diameter which is slightly larger than outer diameter 36 ofthe primary coil. The present intrafallopian device is thereforestraightened to a straight configuration as it is loaded proximally intothe distal end of lumen 56. Elongate body 52 is sufficiently strong torestrain the primary coil in the straight configuration, but must remainsufficiently flexible to allow maneuvering within the body lumen.Elongate body 52 is preferably formed from an inelastic, flexiblematerial such as polyurethane, PET, or the like.

Referring now to FIG. 4, intrafallopian device 10 is released fromdelivery catheter 50 within the fallopian tube by holding shaft 54 whileproximally withdrawing elongate body 52. Distal coil interface surface64 engages the proximal end 14 of primary coil 12. Initially, primarycoil 12 is restrained in a straight configuration by elongate body 52.As elongate body 52 is withdrawn, primary coil 12 is released. Whenprimary coil 12 is unrestrained it forms loop 20; when released withinthe fallopian tube it will generally be restrained by the tubal wall ina configuration between straight and the relaxed secondary shape.Preferably, the first loop released will form a distal anchor bend 66.Subsequent loops will bias primary coil 12 against the fallopian tube,and form a proximal anchor bend, in that order.

Use of the present contraceptive intrafallopian device will be describedwith reference to FIGS. 5 and 6. A uterine introducer canula 70 isinserted transcervically through a uterus 72 to the region of an ostium74. Elongate body 52 is then extended distally from canula 70 into afallopian tube 77, preferably guided under fluoroscopy. Alternatively, ahysteroscope may be used in place of canula 70. Elongate body 52 ismaneuvered using a guide wire 78 past an isthmus 80.

After elongate body 52 extends past isthmus 80, guide wire 78 isremoved. An intrafallopian device according to the present invention isinserted in the proximal end of elongate body 52, the intrafallopiandevice being restrained in a straight configuration by the elongatebody. The device is advanced distally using shaft 54, the shaft andelongate body forming delivery catheter 50 (FIG. 3). Delivery catheter50 is axially positioned so that at least one loop of the intrafallopiandevice is within a target region 84 adjacent to isthmus 80. Preferably,at least one loop is distal of target region 84, and at least one loopis proximal of target region 84 to form the distal and proximal anchorbends of the implanted intrafallopian device.

Once delivery catheter 50 is properly positioned, elongate body 52 maybe axially withdrawn. Shaft 54 axially restrains the intrafallopiandevice at the target location during withdrawal of elongate body 52, asdescribed regarding FIG. 4. As the distal end of the primary coil isreleased, the distal loop forms a distal anchor bend 90. Similarly, theproximal loop forms a proximal anchor bend 92. Intermediate loops arerestrained within the narrow target region 84, exerting substantialanchoring forces against the walls of the fallopian tube. As seen inFIG. 6, the loops need not assume their relaxed form to provideeffective distal or proximal anchors.

The present invention further encompasses permanent sterilization bypassing a current through the shaft to the intrafallopian device afterelongate body 52 has been partially withdrawn, but before theintrafallopian device is fully released. Fallopian tube tissue incontact with the intrafallopian device is dessechated, and thus attachedto the present intrafallopian device. This action also causes permanenttubal damage, leading to the formation of scar tissue which encapsulatesthe intrafallopian device and causes permanent occlusion of the tuballumen. Clearly, the resilient member/shaft interface must be conductiveto allow the present non-surgical method of permanent sterilization.

In conclusion, the present invention provides a contraceptiveintrafallopian device which may be positioned without surgery. While theabove is a complete description of the preferred embodiments of theinvention, various alternatives, modifications, and equivalents may beused. For example, a wide variety of secondary shapes, including openloops, continuous bends, sinusoidal curves, or the like, may be imposedon the primary coil. Therefore, the above description should not betaken as limiting the scope of the invention, which is defined insteadsolely by the appended claims.

What is claimed is:
 1. A sterilization method comprising:inserting aconception inhibiting structure transcervically into the uterus, thestructure having a conductive surface; advancing the structure into anostium of a fallopian tube so that the conductive surface electricallyengages a surrounding tissue; transmitting electrical current from anelectrical conductor, through the structure, and from the conductivesurface into the surrounding tissue so as to affix the conductivesurface of the structure to the surrounding tissue; and detaching theelectrical conductor from the affixed structure and removing theelectrical conductor from the uterus so that the structure remainsaffixed and so that conception is inhibited.
 2. The method of claim 1,wherein the structure comprises a resilient metalic coil, and furthercomprising resiliently engaging the surrounding tissue with the metaliccoil.
 3. The method of claim 2, wherein the structure comprises copper,and further comprising inhibiting conception with the copper of thestructure.
 4. The method of claim 2, wherein the current transmittingstep is performed so as to dessechate the surrounding tissue engagingthe structure.
 5. The method of claim 4, further comprising permanentlydamaging the surrounding tissue.
 6. The method of claim 1, furthercomprising inciting tissue ingrowth into the structure.
 7. The method ofclaim 1, wherein the current transmitting step is performed so as toincite scar formation.
 8. The method of claim 7, wherein the scarformation causes encapsulation of the structure within the surroundingtissue.
 9. The method of claim 8, wherein the encapsulating steppermanently occludes a tubal lumen of the fallopian tube.
 10. Asterilization method comprising:inserting a structure transcervicallyinto the uterus; advancing the structure into an ostium of a fallopiantube so that the structure engages a surrounding tissue; transmittingelectrical current from an electrical conductor, through the structure,and into the surrounding tissue so as to affix the structure to thesurrounding tissue; and detaching the electrical conductor from theaffixed structure and removing the electrical conductor from the uterusso that the structure remains affixed and conception is inhibited.
 11. Asterilization method comprising:inserting a structure transcervicallyinto the uterus; advancing the structure into an ostium of a fallopiantube so that the structure is electrically coupled to a surroundingtissue at a structure/tissue interface; transmitting electrical currentfrom an electrical conductor, through the structure, and directly fromthe structure into the surrounding tissue via the structure/tissueinterface so as to affix the structure to the surrounding tissue; anddetaching the electrical conductor from the affixed structure andremoving the electrical conductor from the uterus so that the structureremains affixed and conception is inhibited.